Tunneling method



Sept. 18, 1945- F. 'P. AYERS TUNNELING- METHOD Filed Nov. 22, 1944 5Sheets-Sheet 1 ,1 F. RAYERS 4 2,385,251

TURNELING METHOD Filed Nov. 22, 1944 5 Sheets-Sheet 2 Fig.2.

Sept. 18, 1945. r F. P. AYERS 2,335,251

TUNNELING METHOD Filed Nov. 22, 1944 '5 Sheets-Sheet 4 Se pt. 18, 19.45.F. P. AYERS. 2,385,251

' TUNNELING METHOD Filed Nov. 22, 1944 5 Sheets-Sheet 5 Fig.1-1. Fig.5.

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Patented Sept. 18, 1945 TUNNELING METHOD Frederick Percival Ayers,Barnstaple, North Devon, England Application November 22, 1944, SerialNo. 564,695 In Great Britain February 22, 1943 12 Claims. (01. 61-44)This inventionhas reference to a method of and means for tunneling, andhas for its object to utilise the tunnel lining'as the foundation of ahelical track on which a travelling cutter-supporting frame, rotatableabout the axis of the bore, can be mounted and driven to run around thetrack, advancing as on a screw-thread gradually and continuously as thecutter or cutters carried thereby skives out the earth, rock or thelike. The track is progressively extended into the bore as the cuttingproceeds.

Briefiy, according'to the invention, the method of tunnelin consists ofstarting a boring, lining it as far as possible with a lining having ahelical track on its inner face, mounting a travelling cutter-supportframe to run on said track to carry a rotary cutter extending in advancethereof, rotating said frame to run around said track screwwise therebyadvancing its rotary cutter into the working face, and continuing thelining in the Wake of the cutter and in advance'of the travellingcutter-support frame to extend the helical track as the boring proceeds.

In carrying out suchla method two main ways of laying the tunnel lining,and consequently the helical track, may be adopted. In one the lining isconstructed of pre-formed sections, and the rotary frame is locatedsufficiently in rear of the cutter to enable fresh liner sections to beplaced in position in advance of the frame and thus to afford a freshlength of helical track to receive the advancing frame as the workprogresses. In another way of laying the lining, the lining is formedand shaped in situ as a layer or skin helically formed trailwise in thewake of the cutter head and again in advance of the travel-'lingcutter-supporting frame, the helical track being formed thereon asthe lining is being moulded in place. Methods of carrying out thisalternative method of laying the lining are set Figure 2 is a diagram ofthe same cutter-sup porting frame as viewed from the right of Figure 1;.j

Figure 3 shows the lower part of the lined tunnel in section, the planeof the'sectionbeing slightly distorted from a plane normal to the tunnelaxis so as, conveniently, to cut through a helical run of the linersections;

- Figure 4 is a diagram referred to later in this specification inconnection with the liner sec Figure 5 is an edge view of a linersection; Figure 6 is a plan of the top edge of the section seen inFigure 5;

Figure 7 is a face view of the concave or interior' side of the linersection shown in Figure 5 but depicted as a flat development thereof;Figure 81s a section on a-a of Figure 7; Figure 9 is a section on b--bof Figure 7;

Figure 10 is a diagram in outline only, also in 'fiat development,ofsome liner sections, as they appear when interfitted in position;

Figures 11 to 14 are views of a shield for use at the working'facedescribed later in this specification, Figure 11 being an elevationshowing the interior, Figure 12 being a similar view but of the exterioror. reverse face, Figure 13 a section on c--c of Figure 11, and Figure14 a side view looking from the left of Figure 11.

Dealing first with the employment of preformed sections, the tunnellining comprises. interfitting sections each formed with a length oftrack so disposed on the section that the helical track isbuilt uparound the inner face of the lining aslthe sections are progressivelylaid in o,the wake of the excavation. Referring mainly to Figures 47'10,the sections I may be cast in arcuate lengths, for example in iron,cement or concrete, with an outer plain or other suitable convex surfaceand. .an interior shallowly recessed and rimmed concave surface, theabutting rims 2 of adjacent sections serving as a convenient means forjoining up the lining as depicted in Figures 1 and 3. The outer convexsurface may be formed with grooves, pockets, scorings or the like asalso may the outer faces of the abutting rims, and by the provision ofholes (not shown) extending through the section from the inner surface,cementor otherrequisite material may be injected to the grooves or thelike for waterproofing or other purposes.

The sections are advantageously longer in the circumferential directionthan in width (i. e. in the height as viewed in Figure 7 thanlaterally), and throughout this length or height the track portion isformed, conveniently in the middle or otherwise (e. g.along.an edge) asmay be found most suitable. This may be in the form of a groove or agrooved rib to take a roller or wheel or its flange, or (as illustrated)in the form of an upstanding V-section or other shaped rail 3 to take agrooved or flanged wheel. At the abutting ends of adjoining sectionswhere the track passes from one section to the other the marginal rim 2of the section is interrupted if necessary so as not to interfere withthe continuity of the track thus built up, as seen at 4 in Figures 6 and8.

The liner sections are, of course, of arcuate curvature as seen inFigures 3 and 5, and for convenience of producing the helical track, maybe given any suitable shape when regarded facially as a flatdevelopment. In one example, this shape is rhomboidal a in Figure 4,which will result in the circumferential joints as the long edges 5winding helically at a pitch determined by the width of the section andthe rhomboidal angles. The joints at the abutting ends 6, where thetrack passes from one to the other are or could be, in this case,parallel to the axis of the bore. In another form (not shown) a plainrectangular shape is used, and in this instance the abutting short edgescomparable to the edges 6 of Figure 4 would be .angularly disposed inrelation tothe axis of the boreto attain the helical progression of theliner convolutions.

In yet another form, and this is the form illustrated in Figures 5 to10, the facial shape is substantially rectangular and the progressivespiral feed forward of the sections brought about by forming short lipsor other projections l Z-wise on the long sides. That :is to say theends of the section are wider than the middle or body .part (by reasonof the outstanding lip 1 extending :partly along .each side fromopposite ends. These square-angled sections would register exactly attheir abutting ends as seen in Figure 10, interfitting at their sides,and by reason of. the aforesaid special shape the circumferential runswould gradually creep spirally out of a plane .normal to the axis of thebore. The track length 3 on each section would be slightly inclined tothe sides as. shown in Figure 7 to produce the-continuousshelimately thecase of Figure 5 it will be clear that.

exactly seven and a half lengths will complete one run, and thus theeighth section to be laid will overlap the beginning of the precedingrun :by half a sections length.

These liner sections with their composite helical track 3, when laid,accommodate a travelling cutter-supporting frame which in principle isscrewed into the working as the boring proceeds.

Any suitable form of travelling cutter-supporting frame and means fordriving it can be used according to the new method of the inventionwhich, as willhave been gathered, consists briefly of starting a boring,lining it as far as possible either by casting in situ orwith sectionspreformed (as in the example just described) which form a helical track,mounting a travelling cutter-support frame to run on said track byimparting a rotary drive thereto within the boring, cutting away theearth, rock or the like by a rotary cutter or cutters carried by :andextending forward of the frame, and fitting-further liner sections orcasting a further length of liner in advance of the frame to extend thehelical track as the tunneling progresses. The liner sections remain insitu as the permanent tunnel lining, the recessed concavities lendingthemselves readily to the attachment of any desired finishing skin. Theflat base or ground of the tunnel may be constituted as shown in Figure3 by flat precast sections 8, bridging from side to side chordwise,engaging convenient rims 2 of the liner sections and supportedintermediately by feet members 9 grooved or otherwise recessed at theirlower extremities to take over other liner rims 2.

Referring to Figures 1 and 2, in one form of travellingcutter-supporting frame and associated apparatus, by way of example, theframe is carried by a three-point roller engagement I0 with the helicaltrack 3. This three-point may be doubled (as seen in Figure 1), trebledor otherwise multiplied lengthwise of the bore toengage more than onetrack 3. The three points are not necessarily equi-angularly spaced fromthe tunnel centre, but preferably spaced to give as much clearance aspossible at one part (such as shown uppermost in Figure 2) for thepassage of liner sections, workmen, cutter replacements and the like.With this end in view the framework comprises a main frame member llparallel to the tunnel diameter and slightly oil centre in. onedirection so as to divide the tunnel transversely into large and smallsegments. The small segment is left substantially clear and the largeone contains the remainder of the travelling framework. The said mainframe member terminates at each end in arunner device l0 engaging thehelical track, e. g. a shoe or carriage, pivoted to the frame and havinga pair of wheels mounted thereon. Another foundation frame member 12extends substantially at right-angles from the frame -I I justdescribed, across the large segmental space, is also off centre, :andsimilarly terminates in a runner device H) engaging the helical track.Other framework I4 is built around the main structural members H and I2.

The said cutter-supporting frame may be driven around its liner track byany suitable means. For example :a central supporting shaft IE3 maybeintroduced for the purposeinter aliaof driving or co-operating withdriving :means. In the case illustrated, for instance, the frame Itl--'l. 2 rotates around a stationary supporting shaft 13 supportedaxially in the tunnel, by means of a suitable bearing I5 forming part ofthe rotary framework previously described. The shaft is carried, at somedistance rearwardly, away from the travelling framework and the workingface, in a supporting framework [6 temporarily riixed or renderedimmobile in 'thetunnel. Thelhear ing at this end, or the said fixedsupporting framework itself, is so arranged that thesnafit may beaxially inclined within limits to take account of bends and deviationsfrom the :axial direction. The shaft may be made tubular for variousreasons, particularly when it "is desired to use "a centrally operatingpilot boring .head 1.60, which could then be mounted inand driventhrough the shaft.

The means for turning the travelling frame may comprise a worm J1 andWorm-wheel 18 gearing between the shaft and frame, the power beingeither manual or derived from an electric motor I9 or other power unitmounted "on the frame, thus in this latter case rendering the travellingframe self-propelling.

The cutter consists of any suitable cutter head 20 having its drivingshaft extending {from "the travelling frame, in driven by a secondelectric motor 2|. or equivalent mounted on the frame. The centre of thecutter is offset from the tunnel centre, and in action it rotates on itsowncentre whilst at the same time advancing bodily bothcircumferentially around the tunnel and forwardly into the working face.This bodily movement is brought about by the helical forward travel ofthe cutter-supporting frame.

In another method of supporting and operating the travellingcutter-supporting .frame (not shown), the central shaft l3.is rotatableand provides the drive for thehelically travelling oper ation. In thiscase the rear end of the shaft is brought through suitable bearings in arear temporarily fixed supporting frame and driven in any way foundconvenient. The shaft is keyed or otherwise fixedly mounted through thetravelling cutter-supporting frame so as to turn the same around itshelical liner track.

At the driven end of the shaft provision is made in the fixed supportingframe for inclinations of the shaft from its original tunnel axis as inthe previous case. For example the rear bearing block carrying the shaftmay be slidably mounted in the centre of the fixed supporting frameworkin such a Way as to be adiustably movable intwo directions diametricallyof the tunnel and at right-angles to one another.

When a central shaft is used, eitherdriven or fixed, there is a spider22 mounted on thefsame in rear of the fixed supporting frame, the radiallegs of which take between respective pairs of cheeks 23 extendingrearwardly from the fixed supporting frame There is a clearance topermit the inclination adjustment previously referred to Whilst thelength of the cheeks is sufficient to enable the spider arms to slidetherein length'ways of the bore. By this means the forward feed of theshaft in relation to the fixed supporting frame I 6 is allowed for.

This latter supporting frame 16 may be clamped in position by jacks 24forced hard against the lining, and through the medium of which, also,the centering of shaft l3 may be adjusted according as the axis ofboring is inclined or not.

Suitable bulkhead arrangements or shields may be employed in conjunctionwith both the working face and in rear of the rear shaft supportingarrangements.

In the first instance, referring to Figures 11 to 14, a bulkhead plateor shield 25 would be shaped to fit closely to the face being worked,and would naturally be of a snail shape to accommodate itself to thepath already skived out. An aperture is formed in the plating throughwhich the cutter extends. In the example the cutting head is housed in atubular casing 25 extending from the plating 25 and this casing isinclined to correspond with the slight inclination given to the axis ofthe head. The cutter attacks the face peripherally at the space 21 aswell as forwardly and axially at 28, the supporting frame rotating in aclockwise direction with respect to Figure 11. The plating 25 terminatesat its out-side periphery in a flange 29 lying parallel to thecircumferential wall of the tunnel. The whole shield would be carried byand rotate with the cutter-supporting frame. The lining may be carriedup to and interiorly overlap the said lip of the shield as in Figure 1where the shield is indicated by broken lines, and in this case, ifnecessary, a suitable configuration may be applied to the liner sectionsto facilitate such an overlap. For example, a step may be formed on theouter face of the section to allow the bulkhead lip to worlgbetween theliner and the soil. The. excavated soilcould be brought ,awayby meansofa chute or other convenient duct leading from the tubular part 26.

Referringnow-to the case where the lining is shaped in situ, the shieldcarrying the cutter may be used to accommodate a roll of sheet metalrotatably mounted thereon with its axis parallel to that of the tunnelso that it would unwind and lie against thecircumferential wall of theboring directly behind the cutting head and its shield.

As the latter rotates and :advances, the sheet slidably mounted on theshaft 3 to facilitate plac sheet of expanded metal, strong wire netting.or

other suitable reinforcement for a cementitious lining. In this case acement lining could be .pressed against the reinforcement as the boringproceeded, and in effect a concrete lining would be cast along thetunneling as the cutter-head moved forward. A quick-drying cement wouldbe necessary, and the interior face would be generally fiat with tracks,raised or recessed, formed for taking the travellingcutter-supportingframe. An elevating device 30 may be rotatably and ing thelinen'sections in position. For example an arm 3| on the device 30 canbe disposed to project forwardly and terminate in any convenient gripperor carrying bracket 32. This latter can be loaded when it is in aconveniently low po- 4Qsition in rear of the travellingcutter-supporting framework, and then the device manipulated to carrythe section to the requisite position.

I claim:

1. A method of tunneling which consists of starting a boring, lining itas far as possible with a lining having a helical track on its innerface, mountin a travelling cutter-support frame to run on said track tocarry a rotary cutter extending in advance thereof, rotating said frameto run around said track screw-wise thereby advancing its rotary cutterinto the working face, and continuing the lining in the wake of thecutter and in advance of the travelling cuttersupport frame to extendthe helical track as the boring proceeds.

2. A method of tunneling according to claim 1 in which the lining iscarried out by laying preformed interfitting liner sections eachconstructed with a length of track so disposed in or on the section thatthe helical track is built up around the inner face of the lining as thesections are progressively laid in the wake of the excavation.

3. A method of tunneling according to claim 1 characterised by theemployment of liner sections which, regarded facially as a fiatdevelopment are substantially rectangular with a short lip on each ofthe long sides at opposite ends 4. A method of tunneling according toclaim 1 in which the travelling cutter-support frame is advancedscrew-wise along the tunnel guided by a central longitudinal shaftmounted in the boring,

5. A method of tunneling according to claim 1 in which the cutting headcarried by the travelling frame is rotated on its own axis, and alsoturns with the helical movement of the frame on which it is mounted, andis driven by a power unit carried by the frame.

6. In a method of tunneling according to claim 1 the employment, of abulkhead or shield against the working face, said shield being securedto the travelling frame, and rotating and helically advancing therewith,

'7. A method of tunneling which consists of starting a boring, lining itas far as'possible with a lining having a helical track on its innerface, mountin a traveling cutter-support frame to run on said track tocarry a rotary cutter-extending in advance thereof, rotating said frameto run around said track screw-wise, thereby advancing its rotary cutterinto the working face, continuing the lining in the wake of the cutterand in advance of the traveling cutter-support frame to extend thehelical track as the boring proceeds, such lining being carried out bylaying precast arcuate interfitting liner sections having an outer planeor other suitable convex surface and an interiorly shallowly recessedand rimmed concave surface formed with part of the helical track, andarranging the rims of ad- Jacent sections in abutting relationship andserving to join the liner sections together.

8. A method of tunneling according to claim '7 in which the track partis in the form of a'rim extending from one end of the liner section tothe other forming a track on which runs a roller, wheel or equivalent ofthe rotary cutter support frame.

.9. A method of tunneling according to claim 7 characterized by theemployment of liner sections, which, regarded facially a a fiatdevelopment, are rhomboidal in shape.

10. A method of tunneling which consists of starting a boring, lining itas far as possible with a lining having a helical track on its innerface, mounting a traveling cutter-support frame to run on said track tocarry a rotary cutter extending in advance thereof, rotating said frameto run around said track screw-wise along the tunnel guide by a centrallongitudinal shaft mounted in the boring, thereby advancing it rotarycutter into the working face, continuing the lining in the wake of thecutter and in advance of the traveling cutter-support fram to extend thehelical track as the borin proceeds and holding said shaft againstrotation while revolving the traveling frame there around through themedium of suitable gearing and a source of power. 11. A method oftunneling according to claim 10 in which the traveling frame carries itsown source of power, such as an electric motor, and drives on to theshaft via a worm gear so as to secure its rotation and thus its helicaladvancement in the direction of the working face.

I 12. In a method of tunneling, according to claim 10, mounting thecentral shaft in a rear framework adapted to be secured temporarily inthe tunnel, and advancing the said framework step by step along thetunnel in the direction of the working face as and when the forward feedof the central shaft necessitates.

FREDERICK vPERCIVAL AYERS.

